Logo image
Effects of Combined Inorganic Nitrate and Nitrite Supplementation on Cardiorespiratory Fitness and Skeletal Muscle Oxidative Capacity in Type 2 Diabetes: A Pilot Randomized Controlled Trial
Journal article   Open access   Peer reviewed

Effects of Combined Inorganic Nitrate and Nitrite Supplementation on Cardiorespiratory Fitness and Skeletal Muscle Oxidative Capacity in Type 2 Diabetes: A Pilot Randomized Controlled Trial

Kristen D. Turner, Ana Kronemberger, Dam Bae, Joshua M. Bock, William E. Hughes, Kenichi Ueda, Andrew J. Feider, Satoshi Hanada, Luis G. O. de Sousa, Matthew P. Harris, …
Nutrients, Vol.14(21), p.4479
10/25/2022
DOI: 10.3390/nu14214479
PMCID: PMC9654804
PMID: 36364742
url
https://doi.org/10.3390/nu14214479View
Published (Version of record) Open Access

Abstract

Nitric oxide (NO) stimulates mitochondrial biogenesis in skeletal muscle. However, NO metabolism is disrupted in individuals with type 2 diabetes mellitus (T2DM) potentially contributing to their decreased cardiorespiratory fitness (i.e., VO 2 max) and skeletal muscle oxidative capacity. We used a randomized, double-blind, placebo-controlled, 8-week trial with beetroot juice containing nitrate (NO 3 − ) and nitrite (NO 2 − ) (250 mg and 20 mg/day) to test potential benefits on VO 2 max and skeletal muscle oxidative capacity in T2DM. T2DM (N = 36, Age = 59 ± 9 years; BMI = 31.9 ± 5.0 kg/m 2 ) and age- and BMI-matched non-diabetic controls (N = 15, Age = 60 ± 9 years; BMI = 29.5 ± 4.6 kg/m 2 ) were studied. Mitochondrial respiratory capacity was assessed in muscle biopsies from a subgroup of T2DM and controls (N = 19 and N = 10, respectively). At baseline, T2DM had higher plasma NO 3 − (100%; p < 0.001) and lower plasma NO 2 − levels (−46.8%; p < 0.0001) than controls. VO 2 max was lower in T2DM (−26.4%; p < 0.001), as was maximal carbohydrate- and fatty acid-supported oxygen consumption in permeabilized muscle fibers (−26.1% and −25.5%, respectively; p < 0.05). NO 3 − /NO 2 − supplementation increased VO 2 max (5.3%; p < 0.01). Further, circulating NO 2 − , but not NO 3 − , positively correlated with VO 2 max after supplementation (R 2 = 0.40; p < 0.05). Within the NO 3 − /NO 2 − group, 42% of subjects presented improvements in both carbohydrate- and fatty acid-supported oxygen consumption in skeletal muscle (vs. 0% in placebo; p < 0.05). VO 2 max improvements in these individuals tended to be larger than in the rest of the NO 3 − /NO 2 − group (1.21 ± 0.51 mL/(kg*min) vs. 0.31 ± 0.10 mL/(kg*min); p = 0.09). NO 3 − /NO 2 − supplementation increases VO 2 max in T2DM individuals and improvements in skeletal muscle oxidative capacity appear to occur in those with more pronounced increases in VO 2 max.
mitochondria nutraceutical oxygen consumption

Details

Logo image